Nikon Projection eyepiece?

ChrisR · Post by **ChrisR** » Fri Oct 16, 2009 3:58 am

Can anyone tell me exactly what this is?

rjlittlefield · Post by **rjlittlefield** » Fri Oct 16, 2009 7:38 am

Google search on nikon cf pl5x gives lots of hits that say "projection eyepiece" or the like, so I think you have the right title. That's what it looks like, too. So I'm thinking there's something puzzling about the device, and then I'm thinking that it doesn't act like an eyepiece when you look through it.

Projection eyepieces that enlarge the image can work like teleconverters. Rather than being a strong positive lens, like ordinary eyepieces, they are a strong negative lens that intercepts the image before it comes to a focus, and moves the focus point farther back so the light has a chance to spread out farther.

Does that help?

--Rik

DaveW · Post by **DaveW** » Fri Oct 16, 2009 8:04 am

Is it not for photography through the microscope? I have just looked it up on the Web and got:-

"Nikon trinocular head with Nikon CF PL5X photo eyepiece."

See page 7 of this link:-

http://www.boycesci.com/Manuals/Microfl ... manual.pdf

DaveW

Cactusdave · Post by **Cactusdave** » Fri Oct 16, 2009 9:38 am

Yes this is a projection photo eyepiece designed to use with the Nikon Microflex film camera. I believe it is optically matched to the Nikon CF N Plan objectives. I don't know how well it would work with other objectives which are not Nikon CFs, but I suspect chromatic abberation would be a problem.

Charles Krebs · Post by **Charles Krebs** » Fri Oct 16, 2009 10:48 am

This is the Nikon "equivalent" of the Olympus NFK. It's a projection eyepiece for Nikon CF objectives, designed to project the objectives primary image directly onto film. They were primarily used in Nikon's microscope cameras, but could also be used with other set-ups. The 5X is far too "strong" for the cameras we use today. It would be most suitable for a film format with a diagonal of about 95mm or a bit smaller. The 2X and 2.5X would be useful for todays DSLR's. The 2.5X would be good for a full frame 24x36mm sensor. The 2X (although still a little too "strong") would be useful for DSLRs with smaller sensors. The 2.5X is fairly common, but you don't see the 2X around very much.

ChrisR · Post by **ChrisR** » Fri Oct 16, 2009 10:57 am

Hmm, thanks chaps. I wonder if I can make use of it.
An impulse buy!
Part of the idea was to cover more field than a standard objective does by direct projection. It'll certainly do that, but lower mag would have been better.

I follow the teleconverter schema, but this one's positive. It forms an image of a reticle too.

Thanks for that link Dave - you have a knack for finding things. I searched of course, but came up with nothing as useful.

It doesn't FIT anything I have - except blu-tack and toilet rolls..

Edit:
missed yours Charles, thanks
Yes I do see 5x is too much really, though I do have a monorail with 5x4 and oddly, 70mm backs..

elf · Post by **elf** » Fri Oct 16, 2009 11:34 am

If I'm interpreting correctly, it sounds like this would be perfect for micro panoramas. You just need a method to shift the camera while holding the lens in one place.

ChrisR · Post by **ChrisR** » Fri Oct 16, 2009 11:40 am

That occurred to me too! The sensor's in a deep hole in the camera though, so once off axis, you wouldn't get a whole frame of extra image.

Presumably someone somewhere has modified flatbed scanners...?

Planapo · Post by **Planapo** » Fri Oct 16, 2009 12:08 pm

Ha! I was just going to ask Charlie what kind of photo eyepieces are to be used with the Nikon CF objectives, and in that very moment I found this posting!

Would these Nikon photo eyepieces fit into the port on the trinocular tube where the Oly NFKs are meant to be used, i.e. can the Nikon CF objectives together with this Nikon CF photo eypiece be used on the Oly BH-2 scopes?

--Betty

ChrisR · Post by **ChrisR** » Fri Oct 16, 2009 12:16 pm

And that was my next question!

Part of the answer to which, is measure the thing. I shall, I shall!
It doesn't fit a CH normal eyepiece tube.

rjlittlefield · Post by **rjlittlefield** » Fri Oct 16, 2009 12:25 pm

elf wrote:...perfect for micro panoramas. You just need a method to shift the camera...

You won't get much extra detail, though. The objective only gives a decent image within a subject field that is the size of an eyepiece field divided by the nominal magnification. That's around 2.5 mm diameter for a 10X objective. You can capture almost all the detail in that field in a single DSLR frame.

To cover a larger field, you have to move the objective (or more typically, move the subject). At microscope magnifications and DOF, this is not a problem for stack-and-stitch. Simply turn off scaling and you'll impose orthographic projection on the composed image. That will eliminate parallax errors.

If your focus movement is smooth and well aligned with the optical axis, then you can turn off alignment altogether. That will make the stacking run faster, as well as eliminating another possible source of error in the computational process. When I write "source of error", I'm talking about misalignments caused by OOF features of the subject that lead the alignment procedure to think that images have shifted when in fact they have not.

--Rik

Charles Krebs · Post by **Charles Krebs** » Fri Oct 16, 2009 4:22 pm

Betty and Chris...

Microscope eyepiece tubes come in two sizes... 23mm and 30mm (inside diameter). I know the current versions of these Nikon projection eyepieces (CFI for "infinity") were made in both sizes. The only "CF" ones I have seen were for 23mm tubes, but if Chris says the one he has does not fit into his Olympus then it's possible that is a 30mm version.

However, even the 23mm versions do not fit properly in the newer BH2 trinocular heads. That because the top part is too wide. Olympus NFK's have a quite narrow upper part. The top tube of the BH2 trinocular head is made so that only these "narrow" eyepieces will fully "seat" into the trinocular tube. So you can insert (a 23mm) CF into the trinocular tube but is will not be able to slide all the way down.

ChrisR · Post by **ChrisR** » Mon Oct 26, 2009 6:15 pm

The narrower part is about 23mm, and it goes into the short tube on a CH head (having unscrewed the eyepiece), but it's quite sloppy. The upper part is about 42mm long and 32mm diameter.
I have what I thought was a standard microscope adapter, but it won't go over the CH lower tube, and the CF eyepiece isn't long anough to poke through it.

I get an image if I drop the eyepiece into the tube and hold the camera some distance above, but without clamping it's not possible to see how good.
I'm not at all sure where the eyepiece should be to get a correct tube length, as it's not designed for a normal microscope, it seems.

Is it "incorrect" to put a projection eyepiece into a tube on a head, designed fot normal oculars? Or should one only be used with a trinocular type vertical tube?
Next question, (other complications aside) is there a way of using an Olympus NFK projection eyepiece with a Nikon body?

Charles Krebs · Post by **Charles Krebs** » Mon Oct 26, 2009 7:09 pm

Chris,

Don't know why you have a "sloppy" fit... there were really only those two sizes commonly used. Usually it's a smooth slide fit, sometimes a little snug.

As long as there is sufficient room to slide the projection eyepiece down a "viewing" eyepiece tube (without it hitting an internal prism or optic... some of those projection eyepieces are pretty long... much longer than a "viewing" eyepiece) it can be done. Would take some "rigging" to align the camera well since an eyepiece tube can't support the weigh of a DSLR.

Normally it would go into a trinocular tube. If the trinocular tube is adjustable you would first bring the subject into focus through the viewing eyepieces. Then put one of the "viewing" eyepieces into the trinoc tube, and adjust it's height until it too is in focus, Then remove the viewing eyepiece and insert the photo-eyepiece. (If you have a "slide-over-the-23mm tube" type of adapter put that on the trinocular head first before inserting any eyepieces).

is there a way of using an Olympus NFK projection eyepiece with a Nikon body?

Not sure what you're asking here. The NFK's do the same thing as the CF you pictured above. The Nikon is "CF" (no chromatic correction) the Olympus is "K"... signifying chromatic correction.

ChrisR · Post by **ChrisR** » Tue Oct 27, 2009 8:38 am

What I'm getting at:
I haven't seen a way so far of using one of the CF eyepieces on a camera body. I'm not sure if they were ever intended to be used outside of a Nikon Microflex.
There's probably something to do it, but

SO how does an NFK fit on to an Om body? Is it via a "standard" T2 microscope adapter. If there is such a thing... If so, presumably one could use an NFK with any body. I realise one would have to use one of the flavors of OM objective, though some (probably the wrong ones) sell cheaply. Eg recently a 10x 0.25 Mplan for about $15.